${{\mathit X}{(1835)}}$ WIDTH

INSPIRE   JSON  (beta) PDGID:
M085W
VALUE (MeV) CL% EVTS DOCUMENT ID TECN  COMMENT
$\bf{ 120 \pm70}$ OUR AVERAGE  Error includes scale factor of 8.8.
$80.7$ $\pm5.2$ $\pm7.7$ 21k 1
ABLIKIM
2024B
 BES3 ${{\mathit J / \psi}}$ $\rightarrow$ ${{\mathit \gamma}}$3 ( ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$)
$245.2$ $\pm13.1$ ${}^{+4.6}_{-9.6}$ 2
ABLIKIM
2016J
 BES3 ${{\mathit J / \psi}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \eta}^{\,'}}$
$192$ ${}^{+20}_{-17}$ ${}^{+62}_{-43}$ 3
ABLIKIM
2015T
 BES3 ${{\mathit J / \psi}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit K}_S^0}$ ${{\mathit K}_S^0}$ ${{\mathit \eta}}$
• • We do not use the following data for averages, fits, limits, etc. • •
$175$ $\pm57$ $\pm25$ 4
ABLIKIM
2018I
 BES3 ${{\mathit J / \psi}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}{{\mathit \phi}{(1020)}}$
$273.5$ $\pm21.4$ ${}^{+6.1}_{-64.0}$ 5
ABLIKIM
2016J
 BES3 ${{\mathit J / \psi}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \eta}^{\,'}}$
$83$ $\pm14$ $\pm11$ 0.6k 6
ABLIKIM
2013U
 BES3 ${{\mathit J / \psi}}$ $\rightarrow$ ${{\mathit \gamma}}$3 ( ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$)
$\text{< 76}$ 90 7
ABLIKIM
2012D
 BES3 ${{\mathit J / \psi}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit p}}{{\overline{\mathit p}}}$
$190$ $\pm9$ ${}^{+38}_{-36}$ 4265 8
ABLIKIM
2011C
 BES3 ${{\mathit J / \psi}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \eta}^{\,'}}$
$57$ $\pm12$ ${}^{+19}_{-4}$ 9
ABLIKIM
2011J
 BES3 ${{\mathit J / \psi}}$ $\rightarrow$ ${{\mathit \omega}}({{\mathit \eta}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$)
$0$ ${}^{+44}_{-0}$ 231 10, 11
ALEXANDER
2010
CLEO ${{\mathit J / \psi}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit p}}{{\overline{\mathit p}}}$
$67.7$ $\pm20.3$ $\pm7.7$ 264
ABLIKIM
2005R
 BES2 ${{\mathit J / \psi}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \eta}^{\,'}}$
$\text{< 153}$ 90 12, 11
ABLIKIM
2005R
 BES2 ${{\mathit J / \psi}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit p}}{{\overline{\mathit p}}}$
$\text{< 30}$ 11
BAI
2003F
 BES2 ${{\mathit J / \psi}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit p}}{{\overline{\mathit p}}}$
1  From a fit of the measured 3( ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$) lineshape that accounts for the abrupt distortion observed at the ${{\mathit p}}{{\overline{\mathit p}}}$ threshold through interference with a second previously unseen narrow resonance near 1880 MeV. The fit uses Breit-Wigner functions for the signal shapes and includes known background contributions. A second solution of the fit gives 37k events.
2  From a fit of the measured ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \eta}^{\,'}}$ lineshape that accounts for the abrupt distortion observed at the ${{\mathit p}}{{\overline{\mathit p}}}$ threshold through interference with a second previously unseen narrow resonance near 1870 MeV. The fit uses Breit-Wigner functions for the signal shapes and includes known backgrounds and contributors.
3  Decay dominated by ${{\mathit f}_{{{0}}}{(980)}}{{\mathit \eta}}$ hence $\mathit I{}^{G}(\mathit J{}^{PC})$ = $0{}^{+}0{}^{-+}$.
4  From a fit to ${{\mathit \gamma}}{{\mathit \phi}}$ invariant mass. Angular analysis consistent with $\mathit J{}^{PC} = 0{}^{-+}$. Other $\mathit J{}^{PC}$ not excluded.
5  Pole width from a fit of the measured ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \eta}^{\,'}}$ lineshape to a Flatte formula that accounts for the abrupt distortion observed at the ${{\mathit p}}{{\overline{\mathit p}}}$ threshold; the fit also includes known backgrounds and contributors, as well as an $\mathit ad~hoc$ Breit-Wigner function (M $\approx{}$ 1919 MeV; $\Gamma $ $\approx{}$ 51 MeV) that is required for a good fit.
6  Superseded by ABLIKIM 2024B.
7  From the fit including final state interaction effects in isospin 0 ${\mathit S}{\mathrm -wave}$ according to SIBIRTSEV 2005A. Supersedes ABLIKIM 2010G.
8  From a fit of the ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \eta}^{\,'}}$ mass distribution to a combination of ${{\mathit \gamma}}{{\mathit f}_{{{1}}}{(1510)}}$, ${{\mathit \gamma}}{{\mathit X}{(1835)}}$, and two states ${{\mathit \gamma}}{{\mathit X}{(2120)}}$ and ${{\mathit \gamma}}{{\mathit \eta}{(2370)}}$, for ${{\mathit M}}({{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \eta}^{\,'}}$) $<$ 2.8 GeV,and accounting for backgrounds from non-${{\mathit \eta}^{\,'}}$ events and ${{\mathit J / \psi}}$ $\rightarrow$ ${{\mathit \pi}^{0}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \eta}^{\,'}}$.
9  The selected process is ${{\mathit J / \psi}}$ $\rightarrow$ ${{\mathit \omega}}{{\mathit a}_{{{0}}}{(980)}}{{\mathit \pi}}$ with B(${{\mathit J / \psi}}$ $\rightarrow$ ${{\mathit \omega}}{{\mathit X}}$ $\rightarrow$ ${{\mathit \omega}}{{\mathit a}_{{{0}}}{(980)}^{\pm}}$ ( $\rightarrow$ ${{\mathit \eta}}{{\mathit \pi}^{\pm}}$ ) ${{\mathit \pi}^{\mp}}$) = ($1.50$ $\pm0.26$ ${}^{+0.72}_{-0.36}$) $ \times 10^{-4}$. Not seen in ${{\mathit J / \psi}{(1S)}}$ $\rightarrow$ ${{\mathit \omega}}{{\mathit K}^{+}}{{\mathit K}^{-}}{{\mathit \eta}}$ by ABLIKIM 2024BQ with 90$\%$ CL upper limit of $9.55 \times 10^{-7}$. This state may be also due to ${{\mathit \eta}_{{{2}}}{(1870)}}$ or to a combination of ${{\mathit X}{(1835)}}$ and ${{\mathit \eta}_{{{2}}}{(1870)}}$.
10  From a fit of the ${{\mathit p}}{{\overline{\mathit p}}}$ mass distribution to a combination of ${{\mathit \gamma}}{{\mathit X}{(1835)}}$, ${{\mathit \gamma}}{{\mathit R}}$ with ${{\mathit M}}({{\mathit R}}$) = 2100 MeV and ${{\mathit \Gamma}}({{\mathit R}}$) = 160 MeV, and ${{\mathit \gamma}}{{\mathit p}}{{\overline{\mathit p}}}$ phase space, for ${{\mathit M}}({{\mathit p}}{{\overline{\mathit p}}}$) $<$ 2.85 GeV.
11  Evidence for a threshold enhancement in the ${{\mathit p}}{{\overline{\mathit p}}}$ mass spectrum was also reported by ABE 2002K, AUBERT,B 2005L, and WANG 2005A in ${{\mathit B}^{+}}$ $\rightarrow$ ${{\mathit p}}{{\overline{\mathit p}}}{{\mathit K}^{+}}$, WANG 2005A in ${{\mathit B}^{0}}$ $\rightarrow$ ${{\mathit p}}{{\overline{\mathit p}}}{{\mathit K}_S^0}$ , ABE 2002W in ${{\overline{\mathit B}}^{0}}$ $\rightarrow$ ${{\mathit p}}{{\overline{\mathit p}}}{{\mathit D}^{0}}$, DEL-AMO-SANCHEZ 2012 in ${{\mathit B}}$ $\rightarrow$ ${{\mathit D}}({{\mathit D}^{*}}){{\mathit p}}{{\overline{\mathit p}}}({{\mathit \pi}}$), and WEI 2008 in ${{\mathit B}^{+}}$ $\rightarrow$ ${{\mathit p}}{{\overline{\mathit p}}}{{\mathit \pi}^{+}}$ decays. Not seen by ATHAR 2006 in ${{\mathit \Upsilon}{(1S)}}$ $\rightarrow$ ${{\mathit p}}{{\overline{\mathit p}}}{{\mathit \gamma}}$.
12  From the fit including final state interaction effects in isospin 0 ${\mathit S}{\mathrm -wave}$ according to SIBIRTSEV 2005A. Systematic errors not estimated.
References